When snapping and rotating an object to the grid along the Z-axis there are small decimal float changes in the details panel.
I informed the user this was a small change and will have little to no effect on their project.
1. Create a new Blueprint First Person project in 4.5.1 or 4.6
2. In the content browser search for the word 'Cube.'
3. Drag the "Template_Cube_Rounded" into your scene.
4. Be sure the snap rotation is toggled 'on' in your active viewport.
5. Rotate your object until you observe the decimal float changes along the axis you are rotating.
Head over to the existingAnswerHub thread and let us know what's up.